@DesertDreams88: Sorry you are dealing with this! It sucks. DS started hitting a bit over a year and a half. At nearly 3, he's much more manageable now. His physical aggression (and our caregivers lack of familiarity with how to deal with it) has been the primary reason in moving him from two different daycares (he's never been formally kicked out.)
I have learned that redirection, showing him how to touch gently etc doesn't work with him. I get down to his level and tell him in a firm voice "I don't want you hitting me. It makes me really sad. " I keep on with this until I see this flash of recognition in his eyes. When I know he "gets it," I tell him to give a hug and say "sorry" and he does that. Then we can go a whole day without an incident.

My son started hitting last January or so. He was almost 3. His main victim was our then 7 month old. It's still happening. He hits her many times a day. He doesn't hit anyone else (other kids) and pre school basically describes him as an angel.

We've tried a LOT of things and clearly nothing has worked. The minor success we've seen is when we praise *every* behaviour that isn't hurting his sister. So if he walks by her without touching her "wow good job walking by so nicely!" Etc. It's exhausting but we've seen some success with that. We'd been in a bit of a downward lately though where we've just been yelling at him to STOP NOW and putting him in time out. It's not working at all. So I think we need to refocus on the praising good behaviour and trying to prevent the bad from happening. It's just hard because I'm home with them all day, and they can be playing so nicely in the toy room while I cook or clean or pee, and then all of a sudden my dd is crying because he hit her.

I'm currently reading how to listen so little kids will talk. Hoping that has some good suggestions.

It started at 18 months on the nose (we got an email from school he was being aggressive in an unprovoked manner) and it was gone within 2 months.

I think the stage was so short for us because we discovered that it was directly related to him not being ready to drop to 1 nap (high sleep needs). We only had the issue at school and he was never aggressive with us. They actually started to be able to pinpoint the exact time he would start being aggressive and redirected him about 30 minutes prior and would have him do something independent / restful (like read). Time remedied it for him.

@DesertDreams88: different for every kiddo. My oldest has never been a hitter. My youngest just tried to hit me today (she's 2.5). It's been going on a few months. One thing I've noticed is she seems really out of control emotionally when she hits, and when I pick her up, I just say I won't let you hit me and I hold down her arm that she's trying to hit me with, and then she'll just collapse on me and sob. It's almost like she's so relieved I'm not mad and I still love her. My oldest is less of an emotional tempest, so it's been an interesting ride with kiddo 2.

@DesertDreams88: I didn't read your other posts, but do you make it a point to first dote on your daughter before addressing your son? That way, she is getting the bulk of the attention for being hit ad opposed to the one hitting getting attention?